I have done several myself. I usually use Hugin (unfortunately the Mac port is slightly behind at this time), manually picking alignment points, then using Photoshop to blend the layers together and fix any issues.So far the largest I have done is 32MP, but I would like to find a good scene to really have some fun with!Here is one that I did this way this summer. It's a view from a peak at Philmont Scout Ranch. I wish that there had been more time on that trip to take pictures, but I have what I have.The full-size image is about 15MP.

Since I do some basic graphic/web design across both PC and Mac, I have done basic visual calibration on all my displays for a gamma of 2.2 and whitepoint of 6500K. (I'll get a real colorimeter one of these days...)

Now I am quite annoyed when I see a monitor with messed-up gamma or the vile 9300K white point.